After a 2 or 3 months deliberating, I bought a Pentax K-x which I received late September 2009. I tried a number of cameras in shops before deciding, including Nikon D3000 / D5000, Canon 500 etc. I did not like the menus and feel of the D5000 so much and I couldn't bring my self to buy a Canon (having been caught out by Canon totally changing the lense mount after FD lenses and me stuck with manual focus camera for many years). In the end the main reasons I selected the K-x were:

It fit my relatively tight budget (ie. Entry Level DSLR)

Pentax has maintained very good backward lense compatibility so the K-x will work with just about any Pentax Lense ever made (more on this later)

I like the size and feel of it (small but felt a nice weight)

Reportably the image quality was very good

Uses standard AA batteries (some people see this as a disadvantage but I certainly love the flexibility AAs give me)

Liked the way the menus were constructed - with one click to access the most common settings (as opposed to D5000 which I found a bit long winded to use)

When I received the camera I was up and running very quickly. Initially I had some battery issues (indicating low battery and shutting down prematurely) but a firmware update fixed this and I was surprised how good battery live was on a set of 2000mAh low leakage batteries (500+ photos). Swapping batteries is easy and a spare set of batteries is very cheap and commonly available.

That said I had mixed results in the first couple of days of shooting. Although I had some experience with SLR shooting this was my first DSLR and there are some significant differences from shooting film. I also think that being able to easily look at images at a detailed pixel level leads one to be more critical of photos than we used to be with film. Even so I soon started snapping some images that were real "keepers" and the volume of images were rapidly increasing!

After a week or so the quality of my snaps increased further (in quality and consistancy) as I tweaked a few settings, mainly:

Focus point centre (rather than 11 or 5 point focus)

Centre weighted exposure (sometime spot metering)

Mostly using Av mode (sometimes Tv or P)

I tend to "Focus and Recompose" (focus with subject in centre of viewfinder, then while holding release half down move the camera to recompose the image as I want) - a habit from SLR days. So I did not care about the lack of focus points showing in the view finder - I have tried selectable focus points on the K-x (it does have them - they just don't show in the view finder) and a couple of cameras since and find it just too slow and fiddly on the ones I have tried so far.

The K-x has an impresive array of settings which are very handy. I enjoy changing setting and seeing which ones suit me better.

Image quality... At first I was not that impressed with image quality but it turns out the problem was that I had to learn how to use a DSLR properly! With high ISO, images are much better on subjects that have fairly uniform lighting (dark areas on image will always have more noise). I now know that this is true on most (if not all) DSLRs. Relative entry level DSLRs, the K-x performs very well at the higher ISO settings and I even have good images that I have blown up to a large size that were taken at ISO 3200!

How do I like the K-x now?
Quite frankly, I love it. No regrets at all. While I can see the benefits that much more expensive (mid / upper level) DSLRs add, there is no doubt that the K-x has huge bang for the buck. With all the creative possibilities it will be quite a while before I get bored with it.